DORCV and valve volume

DORCV and valve volume

Joined: March 1st, 2002, 12:22 am

March 31st, 2012, 3:06 am #1


I mentioned below about how a 39x valve could gain so volume by using a carefully crafted execution of the DORCV setup.

Actaully thats an unintended benefit, the primary being a checkvalve that didnt have the deformation issues thata the factory bit does. Especially in my AC build,

When Steve first mentioned it, the 39x setup was the first thing I thought of. Seems perfect for that......


dr_subsonic's pneumatic research lab

the Lunatic Fringe of American Airgunning
Southwest Montana's headquarters for Airgunning Supremacy
Proud Sponsor of team_subsonic
Quote
Like
Share

Joined: April 1st, 2009, 3:18 am

March 31st, 2012, 5:15 am #2

Taking MSP units and converting them to SSP, then making SSP units MSP.

For the 397 project, cannot wait to get the flat top piston back from Mellon. My educated guess is that one pump will provide close to 400 fps and two pumps around 550 or so, with luck. If it requires three total pumps to hit the 650 mark, that is fine by me.

This particular build will be listed here and/or on the Yellow for sale or trade. Did paint the tube the other day. Used black epoxy based paint. The stuff takes FOREVER to fully cure. Appliance epoxy it is. Used it before with fantastic results, just takes too long to dry for my taste.

Next little build project is another P17 MSP utilizing Steve's direction for the check seal. So simple a solution.

"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
Quote
Like
Share

Joined: September 25th, 2006, 2:19 pm

March 31st, 2012, 3:49 pm #3

Usually the lock washer masks the entire screw head so where will there be room for the o-ring?
Quote
Like
Share

Joined: November 28th, 2002, 6:26 pm

March 31st, 2012, 5:01 pm #4

...intended for use with an Allen socket head would work, since in #4-40, the former has a diam of 0.257", and the latter 0.180"

The difference of ~0.077" would nicely accommodate a 1mm (0.039") width x 4.5mm (0.177") ID = 0.255" OD O-ring.




Steve
Last edited by pneuguy on March 31st, 2012, 5:04 pm, edited 1 time in total.
Quote
Like
Share

Joined: April 1st, 2009, 3:18 am

March 31st, 2012, 5:25 pm #5

If you can understand my quick Microsoft Paint drawing. The screw has a shoulder area. Drilled through the screw is a hole which then takes a 90 degree turn. Due to the dynamic nature of o-rings, the sealing surface would then be upon the drilled hole and the thread area if the thread area should allow air bypass. However, since the screw is a shoulder design, the idea is to seal the threads off and allow the air to only pass through the drilled hole. May or may not work.



"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
Quote
Like
Share

Joined: November 28th, 2002, 6:26 pm

March 31st, 2012, 5:32 pm #6

...just to see if the extra complication, risk, and work buys you anything.

Steve
Quote
Like
Share

Joined: September 25th, 2006, 2:19 pm

March 31st, 2012, 5:46 pm #7

If you can understand my quick Microsoft Paint drawing. The screw has a shoulder area. Drilled through the screw is a hole which then takes a 90 degree turn. Due to the dynamic nature of o-rings, the sealing surface would then be upon the drilled hole and the thread area if the thread area should allow air bypass. However, since the screw is a shoulder design, the idea is to seal the threads off and allow the air to only pass through the drilled hole. May or may not work.



"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
but in deference to pump head space I do this. I discovered this quite accidentally. Where I have a pistol pump which will generate upwards of 5000psi but had no elastomer material which would withstand the heat. So I tried using a steel ball but they have issues of their own.

In the end, I have swapped the steel ball for a viton ball (McMaster Carr) and this has been working well where the valve pressure is unknown(but high) since I am firing a 14.3 at around 750fps/9" barrel with small valve volume.

With the steel ball I did use a low force spring. But found that by pushing the homemade split collar slightly against the viton, the elasticity of the ball offered its own springability.
Quote
Like
Share

Joined: March 1st, 2002, 12:22 am

April 2nd, 2012, 3:09 pm #8

...just to see if the extra complication, risk, and work buys you anything.

Steve
will negate the need for the all the drilling?

dr_subsonic's pneumatic research lab

the Lunatic Fringe of American Airgunning
Southwest Montana's headquarters for Airgunning Supremacy
Proud Sponsor of team_subsonic
Quote
Like
Share

Joined: November 28th, 2002, 6:26 pm

April 2nd, 2012, 3:58 pm #9



Steve
Quote
Like
Share